The marquis of Lazan, anxious to assist his brother, had drafted five thousand men from the Catalonian army, and taking post in the Sierra de Liciñena, or Alcubierre, on the left of the Ebro, drew together all the armed peasantry of the valleys as high as Sanguessa, and extending his line from Villa Franca on the Ebro to Zuera on the Gallego, hemmed in the division of Gazan, and even sent detachments as far as Caparosa to harass the French convoys coming from Pampeluna. To maintain their communications and to procure provisions the besiegers had placed between two or three thousand men in Tudela, Caparosa, and Tafalla, and some hundreds in Alagon and at Montalbarra. Between the latter town and the investing army six hundred and fifty cavalry were stationed: a like number were posted at Santa Fé, to watch the openings of the Sierra de Muela, and sixteen hundred cavalry with twelve hundred infantry, under the command of general Wathier, were pushed towards the south as far as Fuentes, Wathier, falling suddenly upon an assemblage of four or five thousand insurgents that had taken post at Belchite, broke and dispersed them, and then pursuing his victory took the town of Alcanitz, and established himself there in observation for the rest of the siege. But Lazan still maintained himself in the Alcubierre. [Sidenote: Rogniat.] In this state of affairs marshal Lasnes, having recovered from his long sickness, arrived before Zaragoza, and took the supreme command of both corps on the 22d of January. The influence of his firm and vigorous character was immediately perceptible; he recalled Suchets division from Calatayud, where it had been lingering without necessity, and, sending it across the Ebro, ordered Mortier to attack Lazan. At the same time a smaller detachment was directed against the insurgents in Zuera, and, meanwhile, Lasnes repressing all disputes, restored discipline in the army, and pressed the siege with infinite resolution. The detachment sent to Zuera defeated the insurgents and took possession of that place and of the bridge over the Gallego. Mortier encountered the Spanish advanced guard at Perdeguera, and pushed it back to Nuestra Señora de Vagallar, where the main body, several thousand strong, was posted. After a short resistance, the whole fled, and the French cavalry took four guns; Mortier then spreading his troops in a half circle, extending from Huesca to Pina on the Ebro, awed all the country lying between those places and Zaragoza, and prevented any further insurrections.